"What is imagination? Psychologists tell us that it is the plastic or creative power of the soul; but materialists confound it with fancy. The radical difference between the two, was however, so thoroughly indicated by Wordsworth, in the preface to his Lyrical Ballads, that it is no longer excusable to interchange the words. Imagination, Pythagoras maintained to be the remembrance of precedent spiritual, mental, and physical states, while fancy is the disorderly production of the material brain. Chapter XI"